I'm +1 on either the aliline dye or ammonia fuming (or better, both), and also on the fact that it's gonna be a fair bit heavier than your average stock.
White oak weighs about on-par with hickory, 20% heavier than the heaviest species of ash (which is green ash). In my experience, the individual white-oak trees, or sections of a tree, that produce the nicest figure (and some of it is spectacular) also yield stock that is even denser and heavier than the average white oak.
As mentioned, red and white oak are very different, so different that working with them and the qualities of finished products made from them make them seem like completely unrelated species. Red oak's structure is like a fist full of drinking straws, in fact you can put one end of a short pice of it in a glass of water and blow bubbles through it. This is why it rots so fast. End-grain wicks up water until it's saturated from end to end. It also does that with wood stain, which makes it very hard to finish evenly. In white oak's structure, the drinking straws are all walled-off into separate short cells (more like a bundle of microscopic bamboo stalks). It resists rotting because water can never penetrate the end grain past the first cell wall.
So, what effect does all this have on your project...
First, make sure the material is good and dry before working it. The same structure that keeps it from getting wet inside keeps it from getting dry inside. Probably not an issue if it's kiln dried but if its air dried, it takes MUCH longer to get a white oak plank truly dry inside than most other species we work with.
Also, the surface of well-smoothed white oak is so dense and hard that it doesn't take normal finishes well at all. Someone mentioned that it's very open grained. Think of the stock's surface as being planed-down from a bundle of those tiny bamboo stalks. Every cut cell leaves a little "pore" in the surface. The problem with staining is that if you don't fill those pores, and you use standard wood stains (pigment stains), the dense surface won't absorb much finish but the stain pigment will lay in those pores and look blotchy and terrible. Since fuming is not an applied finish but rather a chemical reaction with the wood's structure, it leaves a perfectly even (though sometimes a bit dull and not very adjustable) finish without having to fill the pores. And oiling or shellacking after fuming can greatly richen the look (think Stickley furniture).
Aniline dyes (alcohol based) solve the problem also because, unlike oil/pigment stains, the alcohol is readily absorbed into the surface and it carries the dye-color in with it.
Never use any acid/iron finish on white oak unless, as others have said, you want it black, really black. Even then, it's not usually a nice, even black, it kinda looks like the surface was stained with ink.
Be aware also that oaks have a naturally-high acid/tannin content which is why they were used in bark leather-tanning. ANY source of iron oxide which contacts the oak will create that acid/iron finish effect whether you want it or not. So if your barrel, lock or any other iron parts in contact with the oak ever get a bit of rust, it may create that black stain on whatever part of the wood it is touching. Again, this is a structural, chemical reaction, not a stain on the surface. It's not something that will wipe or sand off. Something to know going in to this project.
As others have said, sample/test pieces are the very best way to get to a finish you will like and expect. If you can't get enough actual test-scraps from your own blank, just get some white oak from anywhere, it will be very close to the same. If it were my project I'd fume as large a test piece as I could get. After fuming, I'd divide it into squares with masking tape. Just oil one test-square, shellack one, and then try tweaking the tone of the rest with various aniline dyes. Don't buy big cans, just mix your own with SLX alcohol and a few colors of concentrated dye. They're infinitely intermixable. I like TransTint but there's a lot of good choices out there. You'll be able to dial-in a color you'll be really happy with. If you don't like any of the test-panes, just plane off the test surface and start again.
Lastly, be sure to complete ALL steps of your stock's final finish on all test squares. With oak/fume/dyes the top-coats may change the final lookof the finish quite a bit. Do all the steps and you'll know for sure.
Keep us posted. I'm eager to see how it progresses!
-Stonehouse John
